Ambidexters are 'less bright' - The Independent on Sunday 4th November 2007

People who can use both their hands with equal skill may appear to be clever but the truth is they're not even as bright as the left- or right-handed, new research says. "There is a dip in intellectual performance among the ambidextrous relative to left- and right-handers," say the researchers, who found no difference in the performances of left and right handers.

Link to Article